1. Field of the Invention
The invention relates to a method of supplying a power supply voltage to satellite converter block, named "Low Noise Block", during use of a plurality of different receiver-decoders connected to the same Low Noise block by means of a main cable for transmitting an intermediate-frequency signal from the Low Noise block and for supplying a power supply voltage and possibly a low-frequency control voltage to the Low Noise block.
The invention also relates to a television receiver-decoder and to a transfer module, in which units the method is carried into effect.
2. Description of the Related Art
A satellite reception unit comprises a parabolic antenna which concentrates a signal in the range of 12 GHz onto a Low Noise block which converts the signal into an intermediate-frequency signal in the range of 1 GHz, and this signal is transmitted through a cable to a receiver-decoder which selects a channel and demodulates it for generating a video and an audio signal supplied, for example, to a conventional television set. The Low Noise block does not have its own supply but is fed via the cable by a power supply in the receiver-decoder. A problem occurs when one and the same Low Noise block is connected to several receiver-decoders because this presents the risk of conflict between the power supply voltages transmitted through the same cable by several receiver-decoders, and, moreover, it is necessary to split the signal among the different receiver-decoders. A solution to this problem is known from U.S. Pat. No. 5,134,486. In accordance with this patent, each receiver-decoder comprises a switch allowing supply or no supply through the cable, and a distributor module splits the signal among different receiver-decoders. The user must activate the switches himself.